Usually, in an endoscopic surgery, which uses an endoscopic device, the operator performs treatment while having in both hands treatment tools that are inserted into the body cavity. When the operator desires to change parameters or the like of peripheral devices during the surgery, he or she requests an assistant or the like to manipulate a operation panel or the like disposed in a non-sterilization area, or in some cases, he or she can manipulate switches or the like disposed near to himself or herself (sterilization area). However, there are cases in which the operator desires to perform fine adjustment by himself or herself without requesting that other people perform manipulation or cases in which manipulation is difficult to perform due to positions or orientations of treatment tools.
As means for solving the above problem, there is a technique, according to Japanese Laid-open Patent Publication No. 2002-123291, regarding a system for endoscopic surgery having a voice recognition function and performing the changing of parameters, etc., of a peripheral device in accordance with a command input via the voice of the operator.
A technique disclosed by, for example, Japanese Laid-open Patent Publication No. 2002-123291, performs voice recognition based on pattern recognition. Specifically, voice commands are registered beforehand in the system and a command vocalized by an operator is compared with the registered voice commands. When the voice command input by the operator and a registered command are identical to each other, that voice command is recognized.
As for a voice recognition technique, Japanese Laid-open Patent Publication No. 2004-199004, for example, has disclosed a technique by which a difference is calculated between the level data of an input voice (vocal volume) and the level data that was obtained immediately previously so as to perform processes in accordance with the result of comparison between the difference and a reference value. Also, Japanese Laid-open Patent Publication No. 07-146696 has disclosed a technique of measuring recognition ratios. Japanese Laid-open Patent Publication No. 2003-228394 has disclosed, as a technique of performing a voice recognition process on the content input via voice, a technique of determining a noun input by a user via voice on the basis of the first character and the number of characters.